Crank-shaft mechanism for internal-combustion engines.



L. H. COBB.

CRANK SHAFT MECHANISM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED 1mm, 19x3.

1 ,186,749. Patented Junv 13, 1916.

' [ymazzflfobb R. e m, y fliioz'ney STATES .&

JQHNSON, TRUE TEE, 3F EITCHBUBG, "MASSACHUSETTS.

CBANK-SHAFT MECHANISM FOR INTERNAL-GCPIBUSTION ENGINES.

'1 ,isogzec.

Specification of Letters Z'aient.

Application file January 28, 1913. Serial Ho. 7%,642.

Be it known-time I. L'nnm H. G088, a citizcn oi the United States, residing at Fitchburg, in the county of l' orcester and Commonwealth of ivlassachnsetts, have invented a new and useful Improvement in CrnnlcShuft Mechcnisj i for Internal-Corn lmsticn Engines. of which the following, together with the accompanying drawing, is a. specification.

My invention relates to internal cornhus lion engines and more mrticularly to than; portion of such engines including the crank shaft and conneciing rods and the mechanism connecting them. The invention is, fiir'therinore, particularly adapted to such engines having more than one cylinder.

The objects of the invention are to provide an improved constrnciionwhich shzill he very simple and compact and the ports of which shell be so rciaicl and connected as to secure great rigidity and consequcnk, smoothncss in operzlcion. Thesc objects, as well as others, are accomplished by the construction and arrangement of ports as hereinaficr described, the novel "features being pointed out, in the appended claim.

The type of internal combustion engine. to which my invention more particularly relates is that adopted to be used in motorcycles in which the available space for the engine is extremely limited, and the use of hire engine unusually severe owing to the jar and vibration incirient to its oporation, especially in. passing ore rough.

places.

The principles of the inveniiioii will he explained in connection wih one ensho di incnt thereof as shown-in the accompanying drawing, in which Figure 1 a. sectional view on rho lino il ilof'l ig. 2; Fig. 2 is a. silo View of .tho moving parts within the crank case; and Fig. 3 is a view of a. novel form of connector by means of which the two crank pins and cranks shown in Figs. 1 and 2 are iniiintnincd at a constant angular misplacemerit.

Like ports arc indiciilcil in the (ire lav similar reference (hora-Ute i.

l n the form of the invcnncc shown n the drawing the cr: ii; shaft coiizprises two illliltill parts 1 and 2 jonrnolwl he hcnrings 3 and l formed in tho opposite lco of a crank case 5; Carried rigidly on Jhc inner end of the part i or" the crankshafliis a crank 6 in the form of a plate, the/part 1 meeting the crank or plate 6 at a. oint between the two 'ends thereof, as clearly in Fig. 2. An annular block. 7, serving as a flywheel, is attached bj' screws 8 or otherwise, to the opposite ends of the "crank and in a position concentric with l: ie crank sh J The part 2 of the crank also carries at its inner end a platoon crank 9 similar to the crank 6 carried by the firt l. of the Shah. A second annular b ock 10, serving as afly-Wheel, is attached "to the opposite ends of the crank 9 by screws 11,01 otherwise, this fly-Wheel being concentric with the peri; 2 of the crankshaft. The flywheel 7 and crank 6 are separated shlliciently from izhe fiy-Wheel l0 and crank 9 to provide suitable space 12 between them for the conncctihg rods 13 and 1.4 and the conneclor l5.

Project 11;; from the inner face of the crank a cylindrical sleeve 16, the opening tl'irongh the sleeve extended to the outer or oppos e face of the crank 8 and being tapered or conical with its larger encl away from the crank. A similar cylindrical sleeve 17 projects from the inner face of the crank 9, there being conical opening through this sleeve and crank similar to the opening in the sleeve 16 and crank 6.

The connector 15 comprises e body portion 38 in the form a flat plate enfi two pins or studs. 19 and 2G projecting from the cpgio faces and from points near the op oosic filliiiS of the cocly portion 18 of the connector. The st' l9 and 20 are tapered :0 iii occu'ia'icly i'onghtheslcc inc (infer coils oi receive suitable nuts a. i rho their respective tuin thorn firmly in place.

he conical openings i 17 respcctivelmcnrl he sends are ihreaccd to The Ell end 22 are locked to prevent their becoming loose by small locking ch one g. suitable notches in the periohcr more The (list-once hebwecn studs 5.9 and such that the Monks ii and. 9 are mainto by cornice-tor 1.5 at the proper o lisgga em in hc :1 rrimggcine shown in the (l: Wing. the w, wor is M ed to maintain the crooks at on angular o. placement so as to coiiperoie properly with two engine cyl inders set 60 apart about the crank shaf.

fPz-itenterl J1me 13,1916.

to draw the The sleeve 16 and stud 19 form a crank pin upon which the crank end of the connecting rod 13 is pivoted, the sleeve 16 being provided with a suitable antifriction sleeve 24 and the connecting rod 13 being provided with an antifriction sleeve 25 fitting over the sleeve 24. In like manner the sleeve 17 and stud '20 form a crank pin upon which the crank end of the connecting rod 14 is pivoted, suitable antifriction sleeves 26 and 27 being provided between the sleeve 17 and conhectlng rod 14. Annular depressions are formed in'the faces of the cranks 6 and 9 about the bases of the sleeves 16 and 17, and similar annular depressions are also formed in the faces of the body portion 18 of the connector 15 about the bases of the studs 19 and 20. These annular depressions provide widened spaces along the outer faces of the sleeves 16 and 17 into which the journals at the crank ends of the connecting rods 13 and 14 are extended in order to provide sufficiently large bearing surfaces.

The part 1 of the crank shaft carries a grooved driving pulley 28 to accommodate the usual driving belt of the motorcycle.

-The part 2 of the crank shaft is connected in any suitable manner with the engine valves so as to operate them inproperly timed relation with the movements of the pistons within the cylinders.

While I have illustrated the principles of my invention by showing and describing the details of one form thereof, I do not wish to be limited to'such details as it is obvious that certain changes may be made within the scope of the appended claim without departing from the spirit of the invention; but

\Vhat I claim as new and desire to secure by Letters Patent is:

In an internal combustion engine, a crank shaft comprising alined separated members posed faces of said crank plates and said connecting member being recessed in surrounding relation to said pins, and the crank ends of the connecting rods being extended into the recesses so formed.-

Dated this 24th day of January, 1913.

LYMAN H. COBB.

lVitnesses NELLIE WIIALEN, PENELOPE CoMnnnnAcn. 

